This application claims the benefit of Japanese Application No. 2002-245406 filed Aug. 26, 2002, the entirety of which is incorporated by reference.
1. Field of the Invention
The present invention relates to a fryer for controlling an ON/OFF operation of a heating means based on a temperature detected by a temperature sensor so that the temperature of cooking oil is maintained at a set temperature.
2. Related Art Statement
Conventionally, cooking utensils such as fryers used for frying foods in fast food restaurants etc., detect the temperature of cooking oil and control the combustion of a burner to maintain the oil temperature within a predetermined range. This temperature control has been normally conducted by a control of an ON/OFF operation of the burner. For example, the burner starts combustion when the detected oil temperature is below a predetermined range, while the burner stops when the oil temperature exceeds the predetermined range. Thus, combustion is controlled in order to maintain the oil temperature within the predetermined range.
However, there may be various factors effecting a change of the oil temperature, such as an amount or heat capacity of foods and heat quantity of a utensil etc. Therefore, when combustion is carried out based on a fixed temperature, the oil temperature often rises excessively high (namely, an overshoot). To prevent this overshoot, it is necessary to stop the combustion in an appropriate timing before the oil temperature reaches a set temperature. In this procedure, when combustion is stopped too early, it is necessary to ignite the burner frequently, resulting the difficulty in durability of the fryer and accuracy of control of the oil temperature.
Moreover, there would be a gap in an oil temperature change between around the foods and around the temperature sensor due to a lack of the oil temperature distribution and an oil circulation. Accordingly, although the oil temperature around the foods is suitable to stop the combustion, the oil temperature detected by the temperature sensor does not rise enough and the combustion stop timing is badly delayed, which causes an overshoot.
In order to solve the above problems, an object of the present invention is to provide a fryer which prevents an overshoot by controlling the oil temperature accurately.